Molecular characterization of Streptococcus pneumoniae, particularly serotype19A/ST320, that emerged in Krasnoyarsk, Russia

Abstract Streptococcus pneumoniae, a common human pathogen, colonizes the nasopharynx and causes diseases including acute otitis media (AOM). We herein report pneumococcal serotype distributions in children before and after PCV7 vaccination and in patients with pneumococcal disease in Siberian Russia (Krasnoyarsk). Analyses included antimicrobial susceptibility testing, ST typing, a pulsed‐field gel electrophoresis analysis, virulence‐related surface protein gene (VSG) typing with novel primers, and a structural analysis by scanning electron microscopy. A major pneumococcal genotype was drug‐susceptible serotype23F/ST1500 for healthy children (HC) prior to the administration of PCV7. In the PCV7 trial, multidrug‐resistant serotype19A/ST320 emerged in vaccinees after PCV7, exhibiting a PCV7‐induced serotype replacement. In patients, multidrug‐resistant serotype19A/ST320 was evident for AOM. Community‐acquired pneumonia (CAP) isolates showed genetic similarities to the AOM (ST320) genotype, constituting a common non‐invasive AOM‐CAP group. In contrast, meningitis isolates were more divergent. Overall, twenty‐five ST types were identified; five (20%) were Krasnoyarsk‐native. Regarding VSGs, PI‐1 (rlrA/rrgB), PI‐2 (pitA/B), psrP, and cbpA were present at 54.3%, 38.6%, 48.6%, and 95.7%, respectively, with two major VSG content types, PI‐1‐/PI‐2‐/psrP+/cbpA+ and PI‐1+/PI‐2+/psrP‐/cbpA+, being found for HC and non‐invasive diseases, respecti...
Source: Microbiology and Immunology - Category: Microbiology Authors: Tags: Original Article Source Type: research